Smoothing Image

OpenCV and C++

Smoothing, also called blurring, is a simple and frequently used image processing operation. In this repo I apply 'Homogeneous' and 'Gaussian' filter on an image.

OpenCV not installed on my MAC OS

1- Install Homebrew
2- Install OpenCV

brew install opencv

3- Install pkg-config.
pkg-config is a helper tool used when compiling applications and libraries. It helps you insert the correct compiler options on the command line rather than hard-coding values. This will be helpful for finding the correct linker flags for OpenCV. This will be more clear in the subsequent steps. To install pkg-config using brew, open a terminal and paste:

brew install pkg-config

4- View OpenCV linker flags.
To view the linker flags for OpenCV, run:

pkg-config --cflags --libs path_to_opencv.pc (My is /usr/local/Cellar/opencv/4.1.2/lib/pkgconfig/opencv4.pc)

The output looks like:

-I/usr/local/Cellar/opencv/3.3.1_1/include/opencv -I/usr/local/Cellar/opencv/3.3.1_1/include -L/usr/local/Cellar/opencv/3.3.1_1/lib -lopencv_stitching -lopencv_superres -lopencv_videostab -lopencv_photo -lopencv_aruco -lopencv_bgsegm -lopencv_bioinspired -lopencv_ccalib -lopencv_dpm -lopencv_face -lopencv_fuzzy -lopencv_img_hash -lopencv_line_descriptor -lopencv_optflow -lopencv_reg -lopencv_rgbd -lopencv_saliency -lopencv_stereo -lopencv_structured_light -lopencv_phase_unwrapping -lopencv_surface_matching -lopencv_tracking -lopencv_datasets -lopencv_text -lopencv_dnn -lopencv_plot -lopencv_xfeatures2d -lopencv_shape -lopencv_video -lopencv_ml -lopencv_ximgproc -lopencv_calib3d -lopencv_features2d -lopencv_highgui -lopencv_videoio -lopencv_flann -lopencv_xobjdetect -lopencv_imgcodecs -lopencv_objdetect -lopencv_xphoto -lopencv_imgproc -lopencv_core

The above shows you the includes and the libraries for OpenCV.

5- Compile the C++ code:

g++ -ggdb $(pkg-config --cflags --libs path_to_opencv4.pc) -std=c++11 filters.cpp -o filters

6- Run the execution file to show filters.

./filters

This will use default image nature.jpg, but you can give another image like this:

./filters path_to_your_image

Future work:

1- Add more filters to cover all types of filters.
2- Add better GUI to enable user to select image and desired filter as well.

If you have any questions, don't hesitate to contact me via: arashzjahangiri@gmail.com